Attachment-plug.



G. vv. NORGATE. `ATTACHMENT PLUG. APPLICATION FlLED DEC.28. 1914.

1,287,082. Patented De@.10,1918.

2 SHEETS-SHEET 1.

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ATTACHMENT PLUG.

APPLICATION FILED DEC. 28. 19H. 1,287,082. Patented Dec. 10, 1918A 2 SHEETS-SHEET 2- UNITED vsra'ras- ,PATENT oFFIcE.

GEORGE WALTER NORGATE, OF CHICAGO, ILLINOIS, A SSIGNOR TO BENJAMIN ELECTRIC MANUFACTURING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

ATTACHMENT-HUG.

Be it known that l, (luenen WALTER Non- GA'rn, a citizen of the United States, residing at Chicago, in the county of 'Cook and State of Illinois, have invented new and useful Iml'novements in Attachment-Plugs,

847,385, filed June 26, 1914, in which an inl sertible member is provided with a spring coil surrounding it which may be forced into engagement with' the threads of the shell contact of the lamp socket.

, One of the objects of my invention is,to

simplify ythe construction of plugs of this character and' increase the efliciency.

Further objects will appear from'the'detailed description i to follow.

In the accompanying drawings n'which I have illustrated one embodiment of my invention- Figure 1 is'an alliial section through my improved plug, showingA the manner 1n which it engages the lamp soclt, andshowing the spring ring ment with the` threaded contact of A the socket;

Fig. 2 is a section sinllilar to Fig. 1 showing the cam disengaged from the sp1iug ring and the spring ring in contracted position;

Fig. 3 1s a section on'the line 3-41201 Fig.

1 showing the spring ring disengaged .from the threaded contact;

Fig. 4 is a similar section 'showing the spring ring engagmgthe contact.;

Fig. 5 is a perspective view of. a flangedretaining member showing the helical shoulder for holding thespring ring inpla'ce;

Fig. (l is a perspective viewcof .the shellv member which 'supports the spring coil showing the helical` shoulder on which the spring coil rests;

Fig. 7 is a perspective view of av sleeve member ln'ovided with cam projections for engaging the spring coil;

Fig. 8 is a perspective view of an insulating base forming a support for the shouldcredshell and the retaining member;

Specification of Letters Patent.

to each other.

expanded into engage.

Patented Dec. 10, 1918.

Applicationfiled December 28, 1914.v Serial No. 879,247.

Fig. 9 is a coil; and

Fig. 10 is an elevation of the spring coil showing the relation of the ends ofthe coil Referring now to the drawing in detail, reference character 11 indicates in general ka lamp socket comprising an outer metal j casing 12, a sleeve 13 of insulating material such as fiber, and a threaded shell contact 14 insulated from the casin 12 by means. of the sleeve 13. The plug itself comprises an insertible portion indicated in general by 15 and a binding terminal carrying member, vindicated in generalby 16, which also carries the cam for actuating the spring coil.

perspective view of the spring The insertible portion 15 comprises a shell 17 of sheet metahpreferably a brass stamp- 1ng, a flanged retaining member 18 which also maybe a brass stamping, an insulating cap 19, an insulating base 20, and' a hollow rivet 21 extending through the base 20 and -cap 19 to hold the partsof the insertible portion together. The hollow rivet 21 also forms the center contact of the plug which engages the center contact 21a of the lamp socket.

tending flange 27v for engagement withthe `flange24 on the shell 17. The insulating base 20 has its upper end'reduced as at 28 to allow it Ato pass through openings in the shell 17--and retaining member 18. A springicoil. 29 rests on the helical shoulder l The shell 17 is reduced toform a helical shoulder at, 22 onwhich the spring.

taining member valso basan inwardly ex-`4 22 and is held in place thereon by its engageme'nt with the shoulder 26 on there,

taining member 18.

The binding terminal carrying 'member 16 comprises Va contactshell 30 which is provided with cam projections for engagement with the spring coil, an insulating base 31 and a cord supporting shell 32 of sheet metal, preferably brass, which also forms a hand grip for inserting the plug in the of the bindingv terminal to telescopewithin the shell 17 socket. The contact shell 30 has a number ot' upwardly projecting cam members 33 which exten'l through the openings 25 in the shell 17 and are provided with cam surfaces 31 for engagement with the spring coil 29. A pin 35, secured in the shell 30 and base 31 in any suitable manner, engages'a lslot 36 in the shell 17 to lim-it tlie sliding movement carryin member with respect to the insertible portion 15. A contact plate 37 embedded in the insulating base 31 is provided with a binding screw 38 and is secured to the contact shell 30 in any suitable manner as by` a rivet 39. .A binding plate 40 also embedded in the insulating base 31 is provided with a binding screw 41 and is connected by'means 'of a rivet 42 with a contact member 43 (which may be a vsplit pin) which engages the center contact 21 of the insertible portion. The ing shell 32 is provided with a threaded portion for engagementwith a correspondingly threaded portion on the base 31. Within the shell 32 is a cup shaped insulating member of any suitable material, such as fiber. The conductors connected to the binding posts 38 and 41 are knotted together, as shown at 46, so that a pull Aon the conductors will not transmit a strain on the binding posts but 'will be taken care of by the shell 32.

The operation ofniy improved deviceis as follows: ssunung thatvthe parts are 1n the position shown in Fig. k2 in-whih Athe cams 33are'disengaged from the spriig coil v 29 and the latter is iii its contracted position, the insertible portion 15 of 'he plug the lamp socket 1l uny is introduced within til ther-enter contact 21 on the plug engages the center eontact 2 1l ou the socket. As Soon as v,the contact 21 comes solidly intoI engage-r iiient with the contact 21 further vinward presure on tlieplug iaees 34 to come into engagement willi the spring coilv 2f) to force the latter outwardly into engagement witli-ilie threads oi' the shell contact 1l. In ease the spring coil 29 is not in just ilie right position to engage the threads on the shell r'oiilar't ll the plug is rotated slightly iii one direction voi' thlc other unl il the parts are. in just the right positioii.

structed'ilia! when :i

pull is exerted on the conductors secured to the binding terminals 33 ind 4l the cani iiieiuliei's 33 will be witli-` Ithe ,spring ,i

drawn from' eiigageiiienlwith roil29 permitting the latter to contract so that'theplug maY lie withdrawn from; the The electrical eoiiection between lthe.l

the split pin 43 which slidablvcngagesthe' contact 2l, the rivet 4-2, and the contact plate lgage the threads of a lamp y forcing said vspring into cord supporti will cause `theshell-lO and the cam lt will he noted that this plug is so cone,y

`.said first flangia a 40. The electrical connection between the threaded shell contact 1-1 of the socket v and the binding terminal 38 is through the spring coil 29, the shell 17, the contact shell 30, the rivet 39 and the binding plate 37. 70

Having thus described my invention that I` claim `as new and desire to secure by Let: ters Patent is;

1 An attachment plug includingan insertible member, a helical spring surrounding said member of a size and shape t0" ensocket, and means movable axially with respect to the plug for contact with said socket, said member being provided with ,I means for preventing endwise movement of said spring thereon in either direction.

2. An attachment plug including an insertible member comprising a shell having a helicalshouldei', and a retaining member secured to said-shell, and having a' helical shoulder adjacent said first shoulder, and a helical springheld in place between said shoulders.-

3. An attachment plug including an in,- sertible member comprising a' shell having a' helical shoulder'provided with afslot, a. helical,spiingengaging said shoulder, and cam meansextending through said slot to engage said' Spring. f 95 4. An attachment 'plug includin an in-` sertible memberomprising a shell1 having a helical shoulder and `an inwardly extendingr flange, and a retaining member secured to said shell and having a helical shoulder. and aiiinwardly extendingr flangeadjacent said first flange, and a helical spring held in4 plaee between said shoulders, an insulating base'engaging` the shell liange, an insulating cap engaging the other flange, and means `tor-securing saidinsulating-liase and cap togethei' to hold the flanges tlierebetweeii.` 5. An attachment plug including an insertilile meliiber comprising a shell havin a. lielieal'shoulder and an inwardly extend- "ing fia-nge, andl alretaining member secured to said shell and having a helical shoulder A, aiid aniiiwardly exteii'diiigl'lauge adjacent, said first iiinge, a helical spring held in place. between said shoulders, an insulating base. eiigagipg the shell flange. an insulating cap'engagiiig'tlie other flange. and u. center eontaet for securing said'iiisulatiiig base andv v eapmgetlier to hold the flanges?therebetween. n i. 6. An' ,i'ittaelimeut plug iiieliuling an iiisertilile n ieniber ooii'iprisiiig a shell having a helical shoulder and.aiiiiiwardly extend ing llauge, and aretaiiiing member serured .to said "filiell and liavingai yhelical shoulder '125 and :iii inwardly?extending flange adjaeeiih lielieal spring held iii placelietweeu saidishouldo'rs, :in insulating hase engaging tliesliell llange. a'ii insulating rap engaging the other llange, and aliollow 1130 rivet forming a center contact for securing said insulating base and cap together to hold the flanges therebetween.

7. A plug comprising ang insu'litin base, e. Contact supported by Said base an movable with respeettheretointo and out of engagement with the threaded contact of a receptacle, retaining means for holding said movable contact in engagement with the threaded contact, a flexible conductor electrically connected with said movable contact 

